Should be easy enough, though to be completely honest, never really looked at a Mk2, as we've only the Mk1 here - think the Mk2 has got a shroud & I'm not sure how that's held on so it may take a bit more work than with the Mk1, which to change/move the barrel just needs the screw taken out & the locktite breaking (when putting it back, getting the transfer port to align is time consuming/fiddly)

Whoop whoop it's returned from A.S.I and completely fixed. Apparently the dodgey previous owner( who sold it on instead of getting it sorted properly) had replaced breech seals with wrong size and the barrel needed adjusting.Just sesighted scope and it's shooting one hole groups. To say I'm pleased is an understatement.A big thank you to Tony at A.S.I who sorted this (very reasonably I may add) and updated me throughout.I am one happy bunny again.